Synthesis, DFT Study and Antibacterial Activity of some Isoxazoline Derivatives Containing ۱,۴-benzothiazin-۳-one Nucleus Obtained Using ۱,۳-dipolar Cycloaddition Reaction

Novel series of isoxazoline derivatives containing ۱,۴-benzothiazin-۳-one ring (۶a-h) were synthesized via ۱,۳-dipolar cycloaddition reactions of arylnitrile oxides ۵a-d on ۴-allyl-۲-(substituted)-۱,۴-benzothiazin-۳-ones ۳ and ۴ led to polyheterocyclic. Systems. During our work, we mainly focused on the reactivity of nitrile oxides with carbon-carbon extracyclic double bond of the allyl group. The reaction leads exclusively to cycloadducts ۶a-h with a good yield. The compounds were characterized using s spectral data (۱H-NMR, ۱۳C-NMR) and for some structures were also confirmed via single-crystal X-ray diffraction techniques. Density functional theory (DFT) optimized structures at the B۳LYP/ ۶–۳۱۱G(d,p) level are compared with the experimentally determined molecular structure in the solid-state. The HOMO—LUMO behavior was elucidated. The results are in agreement with the experimental data. The newly synthesized compounds ۱, ۲, ۳, ۴, ۶a-g using cycloaddition reactions were evaluated in vitro for their antibacterial activities against some Gram-positive and Gram-negative microbial strains. Several compounds tested showed significant activity.

کلیدواژه ها:

۱ ، ۴-benzothiazin-۳-one ، arylnitriloxides ، ۱ ، ۳-Dipolar cycloaddition ، Isoxazoline ، B۳LYP/۶–۳۱۱G(d ، p) ، Antibacterial activity